weird boost behavior.. opinions please?

[StealBlueSHO]

Super weird question. AND COMPLETE UNEDUCATED SPECULATION ON MY PART FOR BOOSTED RIGS ... Can you punch the throttle 'too fast"? from a 'neutral position'  ... I ask because I drag race and I can flip and hit the gas pedal extremely fast and pull .02-.06 RT's all night long. 

Is this a issue of too much pedal 'too quickly' in manual mode?  When I get back on the gas hard and fast am I overwhelming the ecu's response?

edit not enough diet dew for typing..

Not sure? Here is a third gear pull from my car with AJPTurbo's tune... this was a punch from around 2K rpm's... no issues... smooth all the way through the RPM range...

 

[StealBlueSHO]

I'm just an armchair tuner wannabe but its not what I thought it might be in terms of how it was tuned. I still think its tune related though. No doubt the throttle closing is what you feel, as to why it does that when you ease into the gas in third I am not sure but it doesn't do it on a WOT run. You also have no knock on your WOT run, negative or positive which is surprising, but you do have knock in that part throttle log. I also don't see rail pressure in any of your logs, are you using a different config when logging for your tune revisions? Not sure how anyone is keeping and eye on your fuel pressure with these logs.

Its under the "Fuel Rear Pressure" datapoint.. same as Fuel Rail Pressure. Its measured in MPA's as opposed to PSI...

Just to note.. I too am just an armchair datalog reviewer... correction made.

 

[Scott4957]

Ah thanks. I like that AJP changes all those to stuff I can read and I don't have to math my way though it LOL

 

[TopherSho]

AJPTURBO.. I dropped you a PM.

 

[Scott4957]

He'll come back around, hes a busy dude now that he is tuning!

 

[StealBlueSHO]

Ah thanks. I like that AJP changes all those to stuff I can read and I don't have to math my way though it LOL

Yup, it's fun keeping metric and standard conversion tables in your head... I wonder if that's how people who bilingual see the world...


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[TopherSho]

I am in contact with him now.

Thanks everyone.  I think were going to call this one done.

 

[TopherSho]

Super weird question. AND COMPLETE UNEDUCATED SPECULATION ON MY PART FOR BOOSTED RIGS ... Can you punch the throttle 'too fast"? from a 'neutral position'  ... I ask because I drag race and I can flip and hit the gas pedal extremely fast and pull .02-.06 RT's all night long. 

Is this a issue of too much pedal 'too quickly' in manual mode?  When I get back on the gas hard and fast am I overwhelming the ecu's response?

edit not enough diet dew for typing..

Not sure? Here is a third gear pull from my car with AJPTurbo's tune... this was a punch from around 2K rpm's... no issues... smooth all the way through the RPM range...

It will be nice to get that experience ,  It will be better to get to the bottom of the STFT 20% dumping as well.  But for now not worrying about manual mode causing throttle issues, and undue shock and drive train stress would be great.

 

[StealBlueSHO]

Super weird question. AND COMPLETE UNEDUCATED SPECULATION ON MY PART FOR BOOSTED RIGS ... Can you punch the throttle 'too fast"? from a 'neutral position'  ... I ask because I drag race and I can flip and hit the gas pedal extremely fast and pull .02-.06 RT's all night long. 

Is this a issue of too much pedal 'too quickly' in manual mode?  When I get back on the gas hard and fast am I overwhelming the ecu's response?

edit not enough diet dew for typing..

Not sure? Here is a third gear pull from my car with AJPTurbo's tune... this was a punch from around 2K rpm's... no issues... smooth all the way through the RPM range...

It will be nice to get that experience ,  it will be better to get to the bottom of the STFT 20% dumping as well.  But for now not worrying about manual mode causing issues throttle issues, and undue shock and drive train stress would be great.

The STFT is MOST likely the tune... if you get tuned by AJPTurbo he will smooth it out if it's a tune issue.


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[TopherSho]

The STFT is MOST likely the tune... if you get tuned by AJPTurbo he will smooth it out if it's a tune issue.

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We will find out!

 

[metroplex]

I found that if you are accelerating, let off, then suddenly stab the throttle wide open - it can cause a delay opening the throttle for a full second (verified via datalog). I figured it out and got rid of it, now it feels like a cable throttle. A scenario for this would be merging onto a freeway, having someone cut you off and then leave the lane, and you suddenly opening the throttle to keep up with the rest of traffic only to find yourself sitting idle for 1 second.

 

[StealBlueSHO]

I found that if you are accelerating, let off, then suddenly stab the throttle wide open - it can cause a delay opening the throttle for a full second (verified via datalog). I figured it out and got rid of it, now it feels like a cable throttle. A scenario for this would be merging onto a freeway, having someone cut you off and then leave the lane, and you suddenly opening the throttle to keep up with the rest of traffic only to find yourself sitting idle for 1 second.

Are you using the throttle to control the boost spikes?

I think sometimes because the throttle plate is all over the place, that can introduce some delays. I know the tunes I run where the throttle is not used to control the load, it's much more responsive. Just like a traditional cable controlled throttle.


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[TopherSho]

I found that if you are accelerating, let off, then suddenly stab the throttle wide open - it can cause a delay opening the throttle for a full second (verified via datalog). I figured it out and got rid of it, now it feels like a cable throttle. A scenario for this would be merging onto a freeway, having someone cut you off and then leave the lane, and you suddenly opening the throttle to keep up with the rest of traffic only to find yourself sitting idle for 1 second.

Wow. That is a nice tidbit.. thank you for sharing.  I will Talk with AJPTuner and see if this is something we can work around.. Can you respond to StealBlueSho's question?  i think the info will be helpful!